P V Al’brecht. (1999). Differentiable operators of nearly best approximation. Izvestiya: Mathematics, 63, 631-647. https://doi.org/10.1070 m1999 v063 n04 abeh000249
ISO-690 (author-date, English)P V AL’BRECHT, 1999. Differentiable operators of nearly best approximation. Izvestiya: Mathematics. 31 August 1999. Vol. 63, , p. 631-647. DOI 10.1070 m1999 v063 n04 abeh000249.
Modern Language Association 9th editionP V Al’brecht. „Differentiable Operators of Nearly Best Approximation“. Izvestiya: Mathematics, Bd. 63, August 1999, S. 631-47, https://doi.org/10.1070 m1999 v063 n04 abeh000249.
Mohr Siebeck - Recht (Deutsch - Österreich)P V Al’brecht: Differentiable operators of nearly best approximation, Izvestiya: Mathematics 1999, 631-647.
Emerald - HarvardP V Al’brecht. (1999), „Differentiable operators of nearly best approximation“, Izvestiya: Mathematics, Vol. 63, S. 631-647.